Polypropylene composite material with high flowability and high impact resistance, and preparation method and application thereof

Abstract

The application relates to the technical field of polymer modification, and provides a polypropylene composite material with high flowability and high impact resistance as well as a preparation method and application thereof. The polypropylene composite material is prepared by adopting a degradation method, and the raw materials used include 98.7-99.85 wt% of polypropylene resin base material, 0.05-0.3 wt% of impact flow modification additive DeltaMax 5000a and 0.1-1 wt% of a free radical type initiator. The polypropylene composite material with high flowability and high impact resistance provided by the application is prepared by modifying the polypropylene resin base material by using the toughening agent DeltaMax 5000a in cooperation with the degradation agent, can simultaneously have better flowability and impact resistance, can meet the high requirements of the plastic parts of automobiles, household appliances and the like on the drop resistance and processing flowability, the preparation method is simple and easy to operate, the cost is relatively low, and the method is easy to popularize and use on a large scale.

Description

Technical Field

[0001] This invention relates to the field of polymer modification technology, and more specifically, to a polypropylene composite material with high flowability and high impact resistance, its preparation method, and its application. Background Technology

[0002] Polypropylene (PP) is a general-purpose plastic with excellent comprehensive properties. High-strength, high-toughness PP composites can be obtained through blending. These composites are widely used in the automotive, home appliance, and packaging industries. In the automotive sector, high-impact PP composites have become the mainstream material for car bumpers. Toughening modification is one of the main research directions in PP blending modification, and many research reports have been published both domestically and internationally. High-impact PP developed in this area is widely used as a special material for car bumpers. However, while improving the toughness of PP, how to improve its flowability and rigidity to meet the requirements of larger and thinner products remains a key research focus.

[0003] High melt flow rate (MFR ≥ 90 g / 10 min) ensures the easy processability of polypropylene, allowing for reduced processing temperature, injection pressure, and clamping force during product manufacturing, thereby reducing energy consumption, shortening the molding cycle, and increasing production output. High rigidity enables the reduction of product thickness while maintaining the same mechanical strength, achieving thinner walls for large products, which is significant for weight reduction in automobiles. Higher impact resistance means less elastomer can be added, avoiding increased costs and reduced melt flow rate due to excessive elastomer use. High-impact polypropylene resin with high melt flow rate is widely used in injection molding due to its higher processing efficiency compared to ordinary impact copolymers, and its market profit is significantly higher than that of ordinary impact copolymers.

[0004] Currently, most commercially available high-flow-rate impact-resistant polypropylene is produced using the hydrogen conditioning process, characterized by good flowability and high impact resistance, making it popular with users. However, some manufacturers, due to technological limitations in their equipment, cannot use the hydrogen conditioning process to produce high-flow-rate polypropylene and must instead use an organic peroxide initiator-based degradation method. While the flowability of impact-resistant polypropylene produced by this degradation method may meet user processing requirements, its impact resistance is significantly reduced, failing to meet customer needs. This has become a major problem troubling raw material manufacturers. Summary of the Invention

[0005] The purpose of this invention is to provide a polypropylene composite material with high flowability and high impact resistance, and a method for preparing the same, in order to solve the technical problem of poor impact strength of high flowability and impact-resistant polypropylene produced by degradation methods in the prior art.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] In a first aspect, the present invention proposes a polypropylene composite material with high flowability and high impact resistance, which is prepared by a degradation method using raw materials comprising the following components in the following mass percentages:

[0008] Polypropylene resin base content: 98.7%–99.85%;

[0009] Toughening agent DeltaMax 5000a 0.05-0.3%;

[0010] Free radical initiator: 0.1%–1%.

[0011] DeltaMax 5000a is a performance modifier for polypropylene launched by Milliken Corporation. It is mainly used to optimize the impact resistance of polypropylene resin without significantly reducing its rigidity. It can be used to improve the low-temperature toughness of hydrogen-modified impact polypropylene.

[0012] Using free radical initiators as degradative agents to modify polypropylene resin matrix can effectively improve its flowability, but it also negatively impacts its impact resistance. To avoid a significant decrease in the impact resistance of polypropylene composites, toughening agents need to be added for toughening modification. However, because free radical initiators also affect toughening agents, a larger amount of toughening agent is required to achieve a good toughening effect. Increasing the amount of toughening agent not only significantly increases product costs but also adversely affects the flowability of polypropylene composites. Therefore, it is difficult to prepare polypropylene composites with both ideal impact resistance and flowability using degradation methods.

[0013] During the research process, the inventors of this application accidentally discovered that using DeltaMax5000a as a toughening agent resulted in significantly less adverse effects from free radical initiators compared to other toughening agents. A smaller addition amount could significantly improve the impact resistance of polypropylene composites. Applying it to the degradation method can produce polypropylene composites that simultaneously possess high fluidity and high impact resistance.

[0014] In this invention, the toughening agent DeltaMax 5000a may constitute 0.05%, 0.06%, 0.08%, 0.1%, 0.13%, 0.15%, 0.18%, 0.2%, 0.22%, 0.25%, 0.27%, 0.28%, 0.3%, etc. by mass in the raw materials.

[0015] According to some embodiments of the present invention, the toughening agent DeltaMax 5000a accounts for 0.08 to 0.27% by mass in the raw material.

[0016] In this invention, the mass percentage of the free radical initiator in the raw material can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, etc.

[0017] According to some embodiments of the present invention, the free radical initiator accounts for 0.3% to 0.8% of the mass percentage of the raw material.

[0018] According to some embodiments of the present invention, the free radical initiator is an organic peroxide initiator. Specifically, the free radical initiator used in the present invention may be a commonly available organic peroxide initiator.

[0019] According to some embodiments of the present invention, the organic peroxide initiator is bis-tert-butylperoxide diisopropylbenzene.

[0020] The structure of di-tert-butylperoxide diisopropylbenzene is shown below:

[0021]

[0022] In the polypropylene composite material with high flowability and high impact resistance provided by this invention, the use of di-tert-butyl peroxide diisopropylbenzene as a degradation agent has the advantages of low addition amount, low cost and low odor.

[0023] The polypropylene resin base material used in this invention can be selected from various common grades of homopolymer polypropylene resin or block copolymer polypropylene resin.

[0024] According to some embodiments of the present invention, the polypropylene resin base is block copolymer polypropylene.

[0025] According to some embodiments of the present invention, the comonomer of the block copolymer polypropylene is ethylene.

[0026] According to some embodiments of the present invention, the mass content of the ethylene repeating unit is 5-25%.

[0027] According to some embodiments of the present invention, the melt flow rate of the polypropylene resin base material at 230°C and 2.16 kg is 3.0 to 15.0 g / 10 min.

[0028] According to some embodiments of the present invention, the molecular weight distribution index Mw / Mn of the polypropylene resin base is 4.0 to 7.0.

[0029] In a second aspect, the present invention provides a method for preparing the polypropylene composite material described in the first aspect, comprising: mixing polypropylene resin base material, toughening agent and free radical initiator components, followed by melt extrusion, stranding, cooling and granulation to obtain the polypropylene composite material.

[0030] According to some embodiments of the present invention, the mixing includes mixing in a high-speed mixer for 1-5 minutes.

[0031] According to some embodiments of the present invention, the melt extrusion is performed using a twin-screw extruder.

[0032] According to some embodiments of the present invention, the screw speed of the twin-screw extruder is 100 to 600 r / min.

[0033] According to some embodiments of the present invention, the temperature settings of the twin-screw extruder from feeding to the die head are as follows: 190-200℃, 195-205℃, 200-210℃, 205-215℃, 205-215℃, 200-210℃, 195-205℃, 190-200℃, 185-195℃.

[0034] Thirdly, the present invention provides the application of the polypropylene composite material described in the first aspect and the polypropylene composite material prepared by the preparation method described in the second aspect in the fields of automotive materials, home appliance materials, and especially in automotive bumpers.

[0035] The beneficial effects of this invention are at least as follows:

[0036] (1) The polypropylene composite material with high fluidity and high impact resistance provided by the present invention is prepared by using toughening agent DeltaMax 5000a and degradation agent to modify polypropylene resin base material. It can simultaneously have good fluidity and impact resistance, and can meet the high requirements of plastic parts for drop resistance and processing fluidity in automobiles, home appliances and other products.

[0037] (2) The polypropylene composite material with high fluidity and high impact resistance provided by the present invention is prepared by degradation method. The method is simple and easy to operate, with low cost and easy to promote and use on a large scale. Detailed Implementation

[0038] To make the technical problem to be solved, the technical solution, and the beneficial effects of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely for illustrating this patent and do not limit the scope of protection of this invention in any way.

[0039] Unless otherwise defined, the technical terms used in the following embodiments have the same meaning as commonly understood by those skilled in the art. Unless otherwise specified, the reagents used in the following embodiments are conventional biochemical reagents; the raw materials, instruments, and equipment used in the following embodiments can all be obtained commercially or by existing methods; unless otherwise specified, the reagent dosages are those used in routine experimental operations; unless otherwise specified, the experimental methods are conventional methods.

[0040] In the various embodiments and comparative examples of the present invention, the performance data were tested according to the following test methods:

[0041] (1) Notched impact strength of simply supported beam: Tested in accordance with national standard GB / T 1043.1-2008.

[0042] (2) Melt flow rate (MFR): Determined according to the national standard GB / T 3682-2000 Determination of melt mass flow rate and melt volume flow rate of thermoplastics.

[0043] The materials used in the various embodiments and comparative examples of the present invention are as follows:

[0044] (1) Polypropylene resin base: EP5010C, an ethylene block impact copolymer polypropylene produced by Sinopec Zhongsha Petrochemical Company, with a melt flow rate of 10g / 10min (230℃, 2.16kg), a molecular weight distribution index of 5.8, and an ethylene content of 6wt%.

[0045] (2) Free radical initiator: bis(tert-butylperoxide)diisopropylbenzene.

[0046] (3) Toughening agent DeltaMax 5000a: Milliken Corporation.

[0047] (4) Toughening agent POE8105: DOW Company.

[0048] (5) Toughening agent SEBS R-506A: Hunan Boruikang New Materials Co., Ltd.

[0049] According to the components and weight ratios shown in Table 1, the raw materials were weighed and the polypropylene resin base, toughening agent and free radical initiator were placed in a high-speed mixer and mixed. The uniformly mixed raw materials were added to a twin-screw extruder through the main feed port. After melt extrusion, stranding, cooling and granulation, the high-impact and high-flow composite material was prepared by drying. The mixing time, screw speed and extruder temperature settings are shown in Table 2.

[0050] Table 1

[0051]

[0052] Table 2

[0053]

[0054] The impact strength and melt flow rate of the polypropylene materials or polypropylene composites tested in Examples 1-7 and Comparative Examples 1-4 are shown in Table 3.

[0055] Table 3

[0056]

[0057] The experimental results above show that the polypropylene composite material provided by the present invention uses DeltaMax 5000a as a toughening agent. Compared with polypropylene composite materials using other toughening agents, it not only requires less addition, but also provides significantly better impact resistance to high-flow polypropylene that has been degraded by the initiator.

[0058] It should be noted that the embodiments described above are only for explaining the present invention and do not constitute any limitation on the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory terms, not limiting terms. Modifications can be made to the present invention within the scope of the claims, and revisions can be made to the present invention without departing from the scope and spirit of the present invention. Although the present invention described herein relates to specific methods, materials, and embodiments, it does not mean that the present invention is limited to the specific examples disclosed herein; on the contrary, the present invention can be extended to all other methods and applications with the same function.

Claims

1. A polypropylene composite material with high flowability and high impact resistance, characterized in that, It is prepared by degradation using raw materials comprising the following components in the following mass percentages: Polypropylene resin base content: 98.7%–99.85%; Toughening agent DeltaMax 5000a 0.05-0.3%; Free radical initiator 0.1%–1%; The free radical initiator is an organic peroxide initiator.

2. The polypropylene composite material according to claim 1, characterized in that, The toughening agent DeltaMax 5000a accounts for 0.08–0.27% of the raw material by mass. And / or, the free radical initiator accounts for 0.3% to 0.8% of the mass percentage in the raw material.

3. The polypropylene composite material according to claim 1, characterized in that, The organic peroxide initiator is bis(tert-butylperoxide)diisopropylbenzene.

4. The polypropylene composite material according to any one of claims 1-3, characterized in that, The polypropylene resin base material is block copolymer polypropylene.

5. The polypropylene composite material according to claim 4, characterized in that, The block copolymer polypropylene uses ethylene as its comonomer.

6. The polypropylene composite material according to claim 5, characterized in that, The mass content of the ethylene repeating unit is 5-25%.

7. The polypropylene composite material according to any one of claims 1-3, characterized in that, The melt flow rate of the polypropylene resin base material at 230°C and 2.16 kg is 3.0–15.0 g / 10 min.

8. The polypropylene composite material according to any one of claims 1-3, characterized in that, The molecular weight distribution index (Mw / Mn) of the polypropylene resin base is 4.0 to 7.

0.

9. The method for preparing the polypropylene composite material according to any one of claims 1-8, characterized in that, include: The polypropylene composite material is prepared by mixing polypropylene resin base material, toughening agent and free radical initiator components, followed by melt extrusion, stranding, cooling and granulation.

10. The method for preparing the polypropylene composite material according to claim 9, characterized in that, The mixing process includes mixing in a high-speed mixer for 1-5 minutes. And / or, the melt extrusion is performed using a twin-screw extruder.

11. The method for preparing the polypropylene composite material according to claim 10, characterized in that, The screw speed of the twin-screw extruder is 100–600 r / min; And / or, the temperature settings of the twin-screw extruder from feeding to the die head are sequentially: 190-200℃, 195-205℃, 200-210℃, 205-215℃, 205-215℃, 200-210℃, 195-205℃, 190-200℃, 185-195℃.

12. The application of the polypropylene composite material according to any one of claims 1-8 and the polypropylene composite material prepared by the preparation method according to any one of claims 9-11 in the fields of automotive materials and home appliance materials.

13. The application according to claim 12, characterized in that, The application is on car bumpers.

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